A purine analogue, C5H4N4S, that acts as an antimetabolite by interfering with purine synthesis, used primarily in the treatment of acute leukemia.

• 颈基嘌呤一种含硫类似物，化学式为C5H4N4S，是一种能干扰嘌呤的合成的抗代谢药，主要用于治疗急性白血病